The 33-year-old started 12 regular-season games and one playoff contest for
the Broncos last year.

Koppen took over for J.D. Walton last season after he fractured his ankle
against the Oakland Raiders in Week 4. Walton needs further surgery on his
ankle and could miss a significant portion of the upcoming season.

The Boston College product spent his first nine seasons as a member of the New
England Patriots, winning two Super Bowls. For his career, Koppen has started
all but four of the 136 games he has played.